Please refer below links:
VS 2015 or below: https://marketplace.visualstudio.com/items?itemName=NoahRichards.GradientSelection
VS 2019: https://marketplace.visualstudio.com/items?itemName=LokeshGovindu.GradientSelectionVS2019
VS 2022: https://marketplace.visualstudio.com/items?itemName=LokeshGovindu.GradientSelectionVS2022